| Message ID | 20180907185448.30987-1-kw@fieahl.im (mailing list archive) |
|---|---|
| State | Changes Requested, archived |
| Headers | show |
| Series | cpuidle: enter_state: Don't needlessly calculate diff time | expand |
On Fri, Sep 7, 2018 at 8:55 PM Fieah Lim <kw@fieahl.im> wrote: > > ktime_us_delta() is not that cheap on some platform, > and I think this is also the right thing to do. > While at it, fix some coding style as well. > > Signed-off-by: Fieah Lim <kw@fieahl.im> Fix your changelog at least to say that you optimize the code without changing its functionality. > --- > drivers/cpuidle/cpuidle.c | 17 ++++++++--------- > 1 file changed, 8 insertions(+), 9 deletions(-) > > diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c > index 6df894d65d9e..5f6b2c9b6555 100644 > --- a/drivers/cpuidle/cpuidle.c > +++ b/drivers/cpuidle/cpuidle.c > @@ -247,21 +247,20 @@ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv, > if (!cpuidle_state_is_coupled(drv, index)) > local_irq_enable(); > > - diff = ktime_us_delta(time_end, time_start); > - if (diff > INT_MAX) > - diff = INT_MAX; > - > - dev->last_residency = (int) diff; > + dev->last_residency = 0; > > if (entered_state >= 0) { > - /* Update cpuidle counters */ > - /* This can be moved to within driver enter routine > + /* Update cpuidle counters > + * This can be moved to within driver enter routine, > * but that results in multiple copies of same code. > */ > + diff = ktime_us_delta(time_end, time_start); > + if (diff > INT_MAX) > + diff = INT_MAX; > + > + dev->last_residency = (int)diff; > dev->states_usage[entered_state].time += dev->last_residency; > dev->states_usage[entered_state].usage++; > - } else { > - dev->last_residency = 0; > } > > return entered_state; > -- > 2.18.0 >
On Fri, Sep 7, 2018 at 8:55 PM Fieah Lim <kw@fieahl.im> wrote: > > ktime_us_delta() is not that cheap on some platform, > and I think this is also the right thing to do. > While at it, fix some coding style as well. > > Signed-off-by: Fieah Lim <kw@fieahl.im> > --- > drivers/cpuidle/cpuidle.c | 17 ++++++++--------- > 1 file changed, 8 insertions(+), 9 deletions(-) > > diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c > index 6df894d65d9e..5f6b2c9b6555 100644 > --- a/drivers/cpuidle/cpuidle.c > +++ b/drivers/cpuidle/cpuidle.c > @@ -247,21 +247,20 @@ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv, > if (!cpuidle_state_is_coupled(drv, index)) > local_irq_enable(); > > - diff = ktime_us_delta(time_end, time_start); > - if (diff > INT_MAX) > - diff = INT_MAX; > - > - dev->last_residency = (int) diff; > + dev->last_residency = 0; > > if (entered_state >= 0) { > - /* Update cpuidle counters */ > - /* This can be moved to within driver enter routine > + /* Update cpuidle counters > + * This can be moved to within driver enter routine, > * but that results in multiple copies of same code. > */ > + diff = ktime_us_delta(time_end, time_start); > + if (diff > INT_MAX) > + diff = INT_MAX; > + > + dev->last_residency = (int)diff; > dev->states_usage[entered_state].time += dev->last_residency; > dev->states_usage[entered_state].usage++; > - } else { > - dev->last_residency = 0; Besides, what's wrong with this branch? > } > > return entered_state; > -- > 2.18.0 >
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index 6df894d65d9e..5f6b2c9b6555 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -247,21 +247,20 @@ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv, if (!cpuidle_state_is_coupled(drv, index)) local_irq_enable(); - diff = ktime_us_delta(time_end, time_start); - if (diff > INT_MAX) - diff = INT_MAX; - - dev->last_residency = (int) diff; + dev->last_residency = 0; if (entered_state >= 0) { - /* Update cpuidle counters */ - /* This can be moved to within driver enter routine + /* Update cpuidle counters + * This can be moved to within driver enter routine, * but that results in multiple copies of same code. */ + diff = ktime_us_delta(time_end, time_start); + if (diff > INT_MAX) + diff = INT_MAX; + + dev->last_residency = (int)diff; dev->states_usage[entered_state].time += dev->last_residency; dev->states_usage[entered_state].usage++; - } else { - dev->last_residency = 0; } return entered_state;
ktime_us_delta() is not that cheap on some platform, and I think this is also the right thing to do. While at it, fix some coding style as well. Signed-off-by: Fieah Lim <kw@fieahl.im> --- drivers/cpuidle/cpuidle.c | 17 ++++++++--------- 1 file changed, 8 insertions(+), 9 deletions(-)